Antenna



June 6, 1939. J. L. HATHAWAY ANTENNA Original Filed Feb. 25, 1937 11/[III IIIIIII II INVENTOR J. L. HATHAWAY BY g ATTORNEY Patented June 6,1939 UNITED STATES PATENT OFFICE ANTENNA tion of Delaware Originalapplication February 25, 1937, Serial No.

127,628. Divided and this application November 10, 1937, Serial No.173,790

4 Claims.

My present invention is a division of my copending application SerialNo. 127,628, filed February 25, 1937.

The object of my present invention is to pro- 6 vide an improved antennasystem for use with ultra short wave apparatus.

The antenna of my present invention is particularly adapted to safeguardthe frequency stability and constancy of an ultra short wavetransmitter. In carrying my invention into effect, the antenna structureis electrically coupled to the high frequency tubes of the apparatus sothat undue loading, for example, by contact therewith will not causecessation of oscillation or undesirable changes in frequency. A furtherfeature of my antenna resides in the provision of a novel flexibleantenna support saving the antenna and apparatus associated therewithfrom harm in the event of contact with external objects.

In the accompanying drawing, Figure 1 shows my improved antenna and itsapplication to a short wave portable transmitter; and Figure 2 is anexploded view of my antenna.

Figure 1 shows my improved antenna connected to and energized by a highfrequency transmitter T. The transmitting structure is supported withina metallic case 92 which is preferably of such size and shape that itmay readily be carried about. Passing through an aperture in the top ofcase 92 is a feed through insulator 96 and my improved antenna I issupported on the insulator through the medium of a supporting spring 98.The spring resiliently supports the antenna so that if the antenna isinadvertently struck or brushed against non-yielding objects it willdeflect harmlessly and not be bent or broken. Spring 9-8 also serves toconduct radio frequency energy from the output of the transmitter T tothe antenna I00.

40 The power oscillator tube 90 forming a part of transmitter T feedsits output through a relatively small condenser 94 say, for example, ofthe order of ten micro-microfarads in value to the antenna I00 which maybe approximately one- 45 sixteenth of a wave length in length.

Should antenna I00 be touched or otherwise loaded, condenser 04 willserve to prevent undue load reaction or cessation of oscillations and,of

course, the crystal control which may be used with oscillator tube willserve to prevent any substantial change in frequency.

An exploded view of the mechanical construction of the antenna is givenin Figure 2. The antenna proper in the form of a stiff wire or rod I00is fitted within a chuck consisting of a split threaded portion or boltsection I00 whose split ends are fixed against the antenna I00 by theaction of the knurled nut I02. The bolt section I00 is mounted upon thecoil spring 98, in turn supported by the insulating bushing 96. Bushing96 is provided with a lower section I04 threaded to which is bolt I06extending through bushing 96 and threadedly engaging lock nuts I06, I08and the internally threaded member 1 I 0 upon which the spring 90 issupported.

Having thus described my invention, what I claim is:

1. A short wave antenna system comprising a support, an insulatorcarried by said support, an open helical spring having one end mountedon said insulator and a short straight light weight antenna rod mountedon the other end of said spring.

2. A short wave antenna system comprising a support, an insulatorcarried by said support, an open helical spring having one end mountedon said insulator and a short straight light weight antenna rodremovably mounted on the other end of said spring.

3. A short wave antenna system comprising a support, an insulatorcarried by said support, an open helical spring having one end mountedon said insulator, a split chuck mounted on the other end of said springand a short light weight antenna rod removably mounted in said chuck.

4. A short wave antenna system comprising a support, a feed-throughinsulator carried by said support, a clamping bolt passing through saidinsulator and means for energizing said antenna connected to one end ofsaid bolt, a helical spring having spaced turns mounted on the end ofsaid bolt, a split chuck mounted on the other end of said spring remotefrom said bolt and a light weight antenna rod removably mounted in saidchuck.

JARRETT L. HATHAWAY.

